Process for anticrease finishing textile fabrics consisting of cellulose fibers and mixed fabrics containing cellulose fibers



Patented Oct. 6, 1970 ,791 Int. Cl. D06m 13/12, 13/34 US. Cl. 8-1163 2Claims ABSTRACT OF THE DISCLOSURE impregnation of cellulose fabric at apH of below with dimethylol uron or a lower dialkyl ether of dimethyloluron, drying the impregnated fabric to a residual moisture content ofbetween and 25%, based on the dry weight of the fabric, storing thethusly dried fabric for between 1 and 24 hours under conditionsexcluding air and subsequently rinsing and drying the stored fabric toimpart an anticrease finish to the fabric.

This invention relates to a process for anticrease finishing textilefabrics consisting of cellulose fibers and mixed fabrics containingcellulose fibers. More particularly, t relates to an anticrease finishfor these fabrics with d1- methylol uron and a lower dialkyl etherthereof.

In the wash and wear finishing of textile materials consisting ofcellulose fibers or mixed fabrics with N-methylol derivatives ofnitrogenous compounds two methods have hitherto been used forcross-linking the cellulose for anticrease finishes.

According to the first method, the fabrics are 1mpregnated withsolutions of the N-methylol compounds that further contain an aciddonator, such as ammonium chloride, subsequently dried and cured at anelevated temperature for a certain period of time, e.g., 3 minutes at150 C. This process shall be referred to as "curing process throughoutthe application.

According to the second method, which is known from British Pat.905,044, the textiles impregnated with the finishing agents in an acidicliquor are, immediately after their impregnation batched up and allowedto react whilst still wet. Hereby, a so-called wet cross-linking(crosslinking under wet conditions) of the methylol compound with thecellulose fiber takes place. Therefore, this crosslinking process underwet conditions is termed wet crosslinking process.

By using dimethylol uron or its lower alkyl ethers, however, neitheraccording to the curing nor the wet crosslinking process, wash and wearfinishes are obtained that meet all the present-day desirata. Thus, thetextiles finished according to the curing process exhibit a great lossin tensile strength and abrasion fastness, which is greatly adverse tothe ulterior stability of the clothing made thereof. The finish achievedaccording to the wet cross-linking process provides no improvement ofthe dry-crease resistance, which is required for a favorable wash andwear behavior.

We, now, have found that, using dimethylol uron or its lower alkylethers, excellent effects are achieved that are far superior to thosefinishes hitherto obtained therewith, by effecting the impregnation ofthe textiles with the solutions of the dimethylol uron or its loweralkyl ethers at pH-values ranging below 3, by subsequently drying thetextiles so as to reach a residual moisture content of between 5 and 25%based on the weight of the completely dried fabric, preferably 8 to 15%,storing them for 1 to 24 hours by exclusion of air, and after storage,rinsing and drying. The latter rinsing operation may also be coupledwith a neutralization of the residual acid in the finished fabric bymeans of, e.g., dilute sodium carbonate solution.

The moisture content of the textile material after the incompleteintermediate drying prior to storage, the socalled residual moisture, isof decisive influence on the obtainable effects. Whereas the wet-creaseangles are only little dependent on the residual moisture, thedry-crease angles increases according as residual moisture decreases,which is accompanied by a diminution of the tensile strength. Highwet-crease angles and adequate dry-crease angles with little losses intensile strength are obtained when maintaining, according to the presentinvention, a residual moisture content of between 5 and 25 preferably 8to 15%.

In order to adjust the pH-value of the solutions of dimethylol uronutilizable under the present invention, mineral acids may be employed,such as hydrochloric acid, sulfuric acid and phosphoric acid or alsoorganic acids, such as formic acid or trichloroacetic acid.

Drying of the impregnated material so as to reach the desired residualmoisture content may be done at room temperature (about 20 C.) buthigher temperatures, e.g. 100 C., may also be used.

The most advantageous storage time for the moist textiles depends on thepH-value of the impregnation liquor and the temperature during storage;the storage time may vary from 1 to 24 hours.

The dimethylol uron utilizable under the present invention is, forexample, obtained by saponification of the dimethylol uron dialkylethers at a pH-value of 3-2 and temperatures of preferably 5090 C.

Dimethylol uron dialkyl ethers are prepared in the known manner byshort-term heating of urea with formaldehyde under certain conditionsand by subsequent etherification of the dried reaction mixture with analcohol, in the presence of an acid.

The pH-conditions (pH 3) of the finishing process under the presentinvention are vastly in accord with those of the above-mentionedsaponification process (pH 32). Therefore, on principle, the ethers ofthe dimethylol uron may also be employed in place of the dimethylol uronitself, because they are saponified in the prepared liquor. Employing,however, dimethylol uron ether instead of dimethylol uron, somewhatpoorer effects are always observed, which might be due to an incompletesaponification.

The processes of the present invention are illustrated by the followingexamples in which it is to be understood that all temperatures arespecified in degrees centigrade, and that the invention is not limitedto the specific details of these examples:

EXAMPLE 1 A bleached and mercerized fabric consisting of a cotton poplinmixed fabric was impregnated on the padding machine with an aqueoussolution containing 150 grams/ liter dimethylol uron (in the form of a60% solution), and 17 grams/liter hydrochloric acid (37% by weight), thepick-up of liquor being based on the weight of the air-dried fabric.Subsequently, the impregnated fabric was dried at a temperature of aboutso as to reach a residual moisture content of 10%, batched free fromcreases and wrapped in a plastic sheet, stored for 20 hours, at 20. Atthe end of this period, the fabric was rinsed with water, treated with asolution of 2 grams/liter sodium carbonate at 50, then rinsed again withwater, and finally dried at 70.

Testing of the technological properties of the finished fabric ascompared with the nonfinishcd one yielded the following results:

\Vetcrcase Dry-crease angle angle Tensile Strength, Warp Weft Warp WeftWeft kg.

Finished fabric 145 150 120 127 32. Nou1iuished fabric 88 90 44 02 42. 3

A bleached and mercerized fabric consisting of a cotton poplin mixedfabric was impregnated on a padding machine with an aqueous solutionthat contained, 176 grams/ liter dimethylol uron dimethyl ether, and thepH-value of which had been adjusted to 1.3 with hydrochloric acid; thesqueezing effect was 74% based on the weight of the air dried fabric.Subsequently, the fabric was dried. at 100 to give a residual moisturecontent of 8%, batched free from creases, and wrapped in a plasticsheet, stored for 16 hours at 20. It was further treated as described inExample 1.

Testing of the technological properties yielded the following results:

Wet-crease Dry-crease angle angle Tensile strength Warp Weft Warp W cf tweft kg.

Finished fabric 145 147 115 118 34. 2 Non-finished fabric. 88 92 65 7042. 3

Wet-crease Dry-crease angle angle Warp Weft Warp Weft Finish ed fabric512 110 74 85 Non-finished fabric 88 02 65 70 The data on the test ofthe textile material make obvious the superiority of the humidcrosslinkage (crosslinkage under humid conditions) according to thepresent invention.

EXAMPLE 3 In order to prove the superiority of the humid crosslinkingprocess under this invention over the wet crosslinking process knownfrom British Pat. No. 905,044 in the wash and wear finishing withdimethylol uron, the following comparative test has been conducted:

A cotton fabric consisting of a cotton poplin mixed fabric wasimpregnated on the padding machine with a finishing liquor containing150 grams/liter dimethylol uron in the form of a solution and 40cc./liter 12 N-sulfuric acid. In the first case, the impregnated fabricwas batched up immediately afterwards, and wrapped in a plastic sheet,stored for 3 hours at 20. These conditions correspond to the wetcross-linking process.

Another specimen was dried to give a residual moisture content of 7%subsequent to impregnation, and only then batched and stored for 3 hoursat 20, wrapped in a plastic sheet. These conditions correspond to thoseof the humid cross-linking process under the present invention. In bothcases the stored fabrics were subsequently rinsed with cold water,neutralized with a liquor containing 3 grams/liter sodium carbonate,rinsed again with water, and air-dried.

Testing of the finished fabrics yielded the following results:

The above-given data clearly prove the superiority of the humidcross-linking process under the present invention over the known wetcross-linking process in the finishing with dimethylol uron inparticular the small influence of the wet cross-linkage on thedry-crease angles.

It will be understood that this invention is susceptible to furthermodification and accordingly, it is desired to comprehend suchmodifications within this invention as may fall within the scope of theappended claims.

What is claimed is:

1. A process for imparting an anticrease finish to a cellulose fibertextile which comprises impregnating said textile with a solution ofdimethylol uron at a pH of below 3, drying the impregnated textile to aresidual moisture content of between 5 and 25% by weight, based on theweight of the completely dried fabric, then wrapping the thusly driedimpregnated textile in a plastic sheet, storing the wrapped fabric forbetween 1 and 24 hours, subsequently neutralizing excess acid in saidfabric and rinsing and drying the thusly treated fabric.

2. The process of claim 1 wherein said residual moisture content isbetween 8 and 15 References Cited UNITED STATES PATENTS 2,373,135 3/1945Maxwell 8116.3 XR 3,294,478 12/1966 Sittenfield 8116.3 XR 3,309,3413/1967 Abrahams et a1. 8116.3 XR 3,138,802 6/1964 Getchell 2243 OTHERREFERENCES Marsh: Crease Resisting Fabrics, Reinhold (1962) p. 50.

JOHN D. WELSH, Primary Examiner U.S. Cl. X.R.

